Various packaging techniques have been used to assemble a load of unit products and subsequently wrap them for transportation, storage, containment and stabilization, protection and waterproofing. Products are often stacked as a load on a pallet to simplify handling of the products. The pallet load is commonly wrapped with stretch wrap packaging material. One system uses stretch wrapping machines to stretch, dispense, and wrap stretch packaging material around a load. Stretch wrapping can be performed as an inline, automated packaging technique that dispenses and wraps packaging material in a stretched condition around a load on a pallet to cover and contain the load. Pallet stretch wrapping, whether accomplished by a turntable, a rotating arm, or a vertical rotating ring, typically covers the four vertical sides of the load with a stretchable film, such as polyethylene film. In each of these arrangements, relative rotation is provided between the load and the packaging material dispenser to wrap packaging material around the sides of the load.
It is often desirable to determine the weight of a loaded pallet that is to be wrapped with packaging material. For example, it may be desired to determine the weight of each loaded pallet that will be placed into a truck for shipment. Conventional methods for determining the weight of a loaded pallet involve moving the loaded pallet to a scale, generally with a forklift or other equipment, and then weighing the loaded pallet. After the loaded pallet has been weighed, the load can then be moved to an appropriate stretch wrapping machine for wrapping with packaging material. Alternatively, the loaded pallet can be weighed after wrapping, by moving the wrapped load from the wrapping machine to a scale and weighing the wrapped, loaded pallet. Accordingly, weighing of the load, either before or after wrapping, requires additional processing steps that necessarily increase the time, manpower, and equipment resources needed to prepare a loaded pallet for shipping.
A need therefore exists for apparatus and methods that overcome drawbacks of conventional methods and apparatus for determining the weight of a loaded pallet prior to shipment, such as those described above.